Self-portrait by Miles Davis
For my corpus I have decided to investigate the jazz trumpet player Miles Davis. Davis is known within the jazz and global community as a constant innovator and key figure of jazz music. His method for innovation was to constantly attract upcoming talents and stars within the upcoming current in jazz. He then instructed these youngsters with his own vision of jazz and this was reciprocated by the youngsters how provided him with their own new views.
In my corpus I will try to analyse Davis’ music by answering the following questions:
For selecting the phases, I have looked at the bandmembers Miles had played with during these years and made playlists in Spotify to group these phases. After finishing this crude selection, I could identify six phases:
Early bebop/Charlie Parker phase: 1945-1950
During his formative years, Miles played with the bebop greats like Charlie Parker and Dizzy Gillespie, still mostly as a sideman, only playing solo’s or accompanying the theme of the main player. Bebop is characterized by fast paced, harmonically nimble tunes that follow the standard jazz-structure of theme, solo and theme again.
Hard Bop phase: 1950-1955
After the 40ies, most jazz musicians started to get tired of the musical acrobatics that bebop demanded, and switched to a less complex style of jazz called hard-bop. These are mostly mid-tempo, mellow tunes that follow clear structure and allowed for more space in songs. This is the period in which Miles would collabarate with a lot of different musicians, and would be the birth of his “cool” sound.
Modal phase: 1955-1962
Pushing the limits of hard-bop, Miles wanted to winnow harmonic complexity even further, opting to reduce chord changes to as little as possible, in exchange for focussing on a certain mode (minor and major are the main categories, but come in a lot of variations). This is his most popular period, in which he released the most succesful selling jazz album of all time: Kind of Blue. This period was not entirely all modal though, also containing his collaborations with Gil Evans.
Acoustic experimental phase: 1963-1968
After “dumbing down” the music, Miles wanted to experiment again with harmonies, this time eschewing traditional harmony and pushing for less structured, more atonal music (heavily influenced by the harmonic departures of John Coltrane and the Free Jazz Movement). This is the period of his second great quintet, involving amongst others the youngsters Wayne Shorter and Herbie Hancock.
Erratic Fusion Miles: 1969-1975
With electronic instruments bursting onto the scene, and with his bandmate Herbie Hancock being at the forefront of the revolution, Miles could not be left behind. He surrounded him with some of these frontrunners (Chick Corea amongst others) and went full electrical, except for his trumpet. This period is characterized by long jams in which multiple genres (mostly from the funk/soul and rock influence) were blended with his own sounds, to create an erratic melting pot.
The Lost Period (1975-1980)
Not included in this corpus, in 1975 Miles left music behind following mental issues, drug addiction and overall fatigue. Having arguments with record companies and collaborations that fell through, Miles went on a 5 year hiatus to recenter himself. Perhaps something in the data would provide clues to this sudden departure.
The Last Miles (1980-1991)
After returning, Miles continued on his innovative crusade, this time trying to incorporate the hip-hop and R&B influences of the time into his music. The music itself remained erratic to his death, but Miles showed willingness to revisit his older phases during this time.
From the outset, the Very clearly visible from this slopegraph is the huge dip in Acousticness during his lifetime, other things that are very cleary visible is a general increase in energy, a maximum of liveness during his ’63 to ’68 phase and a decline in overall valence, which increased during his final years. Danceability stayed constant, with a big increase during his last years.
The acousticness drop is easily interpretated, since he mostly switched to electrical instruments later on in life. A more difficult trend to interpret is the valence line. Valence is a measure of joyfulness in music, and as Miles became more erratic, his overall vibe became less joyful, after the hiatus it goes back to his original level, perhaps indicating that this hiatus motivated him to make more joyful music.
As valence dropped, energy rose, which is perhaps an odd combination, because you would assume that energetic music would be joyful music. The energy increase is explained by the increase in Miles increasing erraticness. Although he seems to have solved the balance of valence and energy in his final years. Even increasing danceability as well (perhaps hip-hop influences are responsible for this).
A general trend is clearly visible during Miles lifetime, in which a predominantly low energy and high valence repertoire (1944 - 1954) gradually diversified to cover the entire of the spectrum in 1969-1975, in which he coverd the entire charts. His 1956-1962 years look like a very clear three-way correlations between valence, energy and danceability, as low energy and danceability correspond with low valence. In his 1963-1965 years he stayed constant in these parameters, not showing that much variation, although this seems hard to explain. The 1969-1975 years are all over the place, really showing his erraticness of that time, but also look to be dominated by a lot of very low valence tunes. In his final years there is a big trend towards danceability and high valence, perhaps he refound joy after the dark period?
Miles’ Modes
From the graph in the top left corner, it becomes apparent that Miles had a slight preference for the major key most of his life, although this effect is not substantive and could be due to errors in assigning modes in Spotify. The only really clear difference is during his erratic period, in which Major keys seem to dominate his songs, although from the slopegraph and the earlier valence graph it was visible that these were mostly low valence songs.
Miles’ Tempo’s
Overall, the tempo’s seem to be quite constant during Miles’ lifetime. Interesting is that the spread of the first phase is sloped towards the higher tempo’s (indicating the influence of bebop) and his slowing down during the cool and hard-bop phases. Another interesting outlier is the black dot at the zero mark during his 1969-1975 phase, this is an introduction track of a live album so should be omitted.
Miles’ Keys
In the early years there is a clear preference for the F-key in Miles’ oeuvre. This makes sense, as a trumpet is generally tuned in Bb, with the most comfortable keys being F, Eb and Bb. The 1969-1975 years were mostly comprised of long jams, and the bandleader (Miles) would usually determine the key, which coincides with this comfort key being Bb in those years.
The keys E, Eb and Gb seem to be less favored by Miles, which is interesting because a lot of jazz is written in Eb. With musicians there is however a common tendency that if one favours a specific key (F in Miles’ case), the keys surrounding that key are less favored, because they differ the most from the favourite key (other complimentary keys for F-minor are C-minor, Eb Minor, Ab-minor and complimentary for Major are A, C, D). It turns out that Miles follows this trend to avoid keys near to his favorite key.
Using Dynamical Time-warping, I have compared two renditions of the popular song Summertime (Gershwin). One is recorded on the album Porgy & Bess by Miles in 1959 and arranged/produced by Gil Evans. The other is a 1991 (right before his death) rendition which uses the same arrangement and the same key. The differences between these tracks are that 1991 version is significantly faster (107 in 1959 and 132 in 1991).
For the comparison I only used the theme, as these are similar in arrangement and similar in melody, although very much not equal, since theme’s can vary wildly from eachother in jazz. For this reason, I wanted to compare timbres and not chroma features of the two songs, but to no avail. I used the manhattan normalisation and the euclidean distance to compare songs. But the fact that one was live and the other was a studio recording apparently made comparison very hard.
When trying to compare the songs, A faint diagonal line can be made out around the middle of the graph with parallel lines above and under it, that wobbles a bit untill it disappears again around the 60 second mark. The theme repeats once, so this is visible. You would expect to see the line sloping upwards towards to end, showing that the 1991 version is considerably faster, but this is not visible. The checkerboard pattern does show some promising results in comparing similarities and shows that overall the timbres remain the same. Generally speaking, this would mostly be due to the very similar ensemble timbres. Miles sound was less strong in his later years.
Check out the 1991 Summertime rendition (same recording as on the album)!
Have a listen to the 1959 rendition: